The present invention relates generally to processing methods for silver halide photographic elements, particularly to the reuse of sources of water, particularly wash water, within the processing machine for photographic processing purposes.
It is desirable, especially with small scale dispersed photofinishing equipment or stand-alone equipment, to reduce the number and complexity of operator interventions required to process photographic films. One way to achieve this is to package the processing solutions as concentrates, which are then mixed with water by the operator or mixed automatically by the processing machine to provide the working strength solution concentrations. The KODAK SM system automatically meters these concentrates into the processing machine and adds water, so that no chemical mixing is required by the operator. It is still necessary to provide the machine with water periodically, but these processors essentially are self-contained in that they contain all of the processing solution volumes they require on-board. In highly dispersed photofinishing it is not desirable to have to mix chemicals by hand frequently or to have to provide the machine with water frequently. It is also desirable to minimize waste generated from the processor.
Less expensive and more economical photographic processing equipment can be built if the automatic mixing and dilution of processing chemistry concentrates can be avoided. With these processing machines, processing chemicals are supplied at the working strength required by the processor, eliminating the need to dilute by hand and the need for accurate pumps for automatic mixing and dilution to working strength. This saves cost in manufacturing the processing machine, which also can be self-contained. It is still desirable to minimize the number of interventions required by the operator to replace empty packages of processing chemistry (in liquid or solid form) or to refill the processor with water used for processing. It is also desirable to minimize the volume of processing solutions required to be periodically replaced by the operator, and to minimize the volume of waste generated by the processor.
In single-use photographic processing small volumes of processing solution are used which are similar in size to the volumes used to replenish conventional large tank processors. These small volumes are used to process photographic materials such as negative films without the need for large volume tanks of processing solutions. After the process is complete these small volumes of solution are discarded. Thus the overflow or waste solution volume is similar to that from conventional processors with large volume tanks. In the wash stage of a single-use photographic process it is possible that several wash volumes will need to be added to the processor chamber or container to wash the film and also to wash the processor chamber or container at the end of the process. The first wash is added and after an appropriate time it is removed by some means and the second wash is added. This sequence is repeated for the desired number of washes. If the single-use processor is operated in an environment which does not have a water supply (meaning that the processor is not attached to a permanent water supply) then the total volume of water for washing a given amount of photographic material needs to be provided on-board the processor (it needs to be self-contained). One way to accomplish this is for the chemical supply, which includes the wash water, to be contained in a cartridge which is xe2x80x9cpluggedxe2x80x9d into the machine. When it becomes empty after processing a certain amount of photographic material, the cartridge is removed and replaced by a fresh full cartridge. The size and weight of this cartridge must be limited to that which can be easily lifted and handled by an operator. It is desired therefore that the volumes of processing solutions and wash water be minimized, but it is also desired that the washing of the photographic materials be efficient and thorough, and that as large an amount as possible of photographic material be processed with the minimum volume of processing solutions. At the same time, it is desired to minimize the waste generated by the processor while achieving rapid processing.
EP 932078 (Masson) describes a process and a device for the treatment of photographic film. The film circulates in a series of processing baths in which washing occurs. The waste water from the washing areas is recovered for reuse by a nanofiltration device. There is no teaching in this document regarding the impact of such recycling when applied to processing machines that are self-contained machines which must carry on-board all of the processing solution chemistry and water necessary to process photographic materials. There is also no suggestion in this document that advantages with respect to processing solution consumption, waste generation, or rapid processing would result from recycling a relatively small volume of wash water.
EP 430323 (De Niel et al) describes a device for recovering silver from rinsing water from a photographic processor. The device includes a bed of ion exchange resin which is fluidized by the rinsing water and a holder for ion exchange resin with an inlet for liquid at the bottom.
DE 3034102 (Eder et al) describes the use of strongly basic anion exchange resins to remove silver from photographic wash waters.
These ion exchange methods use strongly basic or weakly basic anion exchange resins to remove the silver-bearing anions from the wash waters in order to recover silver. There is no teaching regarding the recycling of these wash waters and any benefits that might result from doing so. There is also no teaching regarding processing machines that are self-contained machines which must carry on-board all of the processing solution chemistry and water necessary to process photographic materials. There is further no suggestion in these references that advantages with respect to processing solution consumption, waste generation, or rapid processing would result from recycling a relatively small volume of wash water.
The present invention solves the problem of minimizing the volume and weight of wash water required to be provided on-board a self-contained photographic processor to process a finite amount of photographic material. This invention minimizes the waste generated by such a processor, and it permits more rapid processing of photographic materials to be achieved.
An object of the present invention is to provide for a system and method for conserving water on-board a processor, such as a self-contained photographic processor, as well as recovering and reusing the water after it has been used to process photographic material. The total volume of chemistry and water required to process a finite amount of silver halide photographic material (and the volume of waste generated from processing that material) is minimized significantly if a recycled volume of wash water (that has been treated to remove thiosulfate) is used to wash the material in a wash stage of a multi-stage wash sequence that is subsequent to a first wash stage. The wash sequence follows a treatment step with a processing solution with a fixing ability. In addition, the overall photographic process is significantly more rapid and the processing waste volume generated is also minimized. The small volume of water from the first wash stage is discarded to waste. Optional additional wash stages or a rinse may follow the wash stage that makes use of the recycled wash water volume.
The present invention therefore relates to a method for processing photographic material which comprises: providing a photographic material to a processor; supplying a processing solution to the processor to process the photographic material; applying a first volume of washing solution to the processed photographic material during at least one first washing stage; applying a second volume of washing solution to the processed photographic material during at least one second washing stage, with the second volume of washing solution applied during the at least one second washing stage being greater than the first volume of washing solution applied during the first washing stage; and cleaning the second volume of washing solution after the at least one second washing stage.
The present invention further relates to a processing arrangement which comprises: a processor adapted to process photographic material; a solution supply system adapted to supply washing solution to at least processed photographic material in the processor in a sequence in which at least a first volume of washing solution is applied during at least one first washing stage and a second volume of washing solution is applied during at least one second washing stage, with the second volume of washing solution being greater than the first volume of washing solution; and a cleaning assembly adapted to clean the second volume of washing solution after the at least one second washing stage.